Endless belt magnetic separator



Dec. 1, 1953 s. G. lNJEsKl ENDLESS BELT MAGNETIC SEPARATOR Filed March8, 1950 Patented Dec. 1, 1953 ENDLESS BELT MAGNETIC SEPRATOR Stanley G.Injeski, Milwaukee, Wis., assignor to Dings Magnetic Separator Co.,Milwaukee, Wis., a corporation of Wisconsin Application March 8, '1950,Serial No. 148,475

2 Claims. l The present invention relates in general 'to improvements inthe art of separating mixed magnetic and non-magnetic materials, andrelates `inox-e specifically 'to improvements in the conystruction 'andoperation of endless belt magnetic 'separators for effecting automaticseparation of magnetic particles fromnon'e'magnetic substances Vwithwhich the 'former are intermingled.

The primary object lof my invention is to provide an improved endlessbelt type lof magnetic separatorlwhich is exceedingly simple and compactconstruction, and which is 'also highly eicient in operation.

It is common practice in the mining industry, tov separate magnetic oreparticles from nonmagnetic substances with the aid of a bank 'ofmagnets'coacting with the lsagging lower run of `an endless materialconveying belt, and wherein the mixture is fedV against 'fthe lower faceof the belt at' one end of the magnet group and the separated magneticparticles are delivered from the belt beyond the magnets while thetailings are removed between the feed and discharge zones. Thisseparation is usually effected in a bath of liquid with the aid of arubber surfaced material advancing belt which should constantly snuglyvengage the magnet bank; and in order to main- .'tain the lower belt runin" proper engagement with the magnetic polesk it has heretofore beencustomary to utilize a manually operable belt tightenerfor periodicallyspreading the belt supporting pulleys apartwhenever undesirable beltvstretch becameapparent to the operator. This prior method ofcompensating for belt wear and stretch is not satisfactory unlessoperating conditions are continually and carefully observed; and whilevsome of the prior separators `of this type have also been provided withther various devices for preventing delivery of excess treating liquidwith the concentrates, these have also proven to be a constant source ofannoyance. l

It is thereforev an important object of the present-invention toprovideimproved mechanism for constantly and effectively compensatingfor variations in'belt lengths ink magnetic separators of the endlessbelt type, with minimum attention on the part of thefoperators, whilealso `insu/ring .most effective driving contact between the belts andtheir driving pulleys.

Another importai'itY object of this invention is to provide improvedstructure for automatically and effectively dew'atering the concentratesor magnetic material delivered by an endless Vbelt magnetic separa-tor',without the use of complicated mechanism, :and for-v -also removing?excess treating liquid from the separating zone.

A further important object of the invention is to provide a compact buthighly ei'cient maglnetic separator of great capacity, all relativelydelicate parts of which are normally well protected while being Yreadilyaccessible for inspection and adjustment.

Still another important object of my invention is to provide a simpleand durable automatin cally functioning magnetic separator especiallyadapted for the constant and effective treatment of low grade ferrousore with minimum loss `of time due to necessary repairs.

These and other more specific objects andl advantages of the inventionwill be apparent from the following detailed description.

A clear conception of the several features constituting my invention,and of the l'construction and operation of a typical endless beltmagnetic separator embodying the same, may be had by referring to thedrawing which accompanies and forms a part of this specification, andwherein like reference characters designate the same or similar parts ofthe structure. Y

The sing-le figure of the drawing is a somewhat diagrammatic sideelevation of one of vmy improved magnetic separating units,.lookingtoward the driving mechanism and with a portion of the casings brokenaway soA as to reveal a normally concealed structure.

The gist of the present invention is the provi- -lsion of improvedinstrumentalities for insuring proper advancement and coaction of theendless conveyor belt with the .pulleys and magnets, and for handlingthe treating liquid so as to constantly remove the excessfand to preventundesirable escape of polluted liquid with the` concentrates, and whilethe typical embodiment illustrated involves a conveying belt having itslower stretch or run substantially disposed along a catenary curve andcooperating with the magnets to produce only a single separation ofyconcentrates from tailings, it is not my desire or intent tounnecessarily restrict the utility of the improvement by virtue of thislimited showing. It is also contemplatedv that specific descriptiveterms used herein be given the broadest possible interpretationconsistentv with the actual disclolSure.A

Referring to the drawing, the improved magnetic ore separating unitshown therein comprises in general, a continuously advancing endlessbelt .El coacting with van upper driving pulley 4 and with a lower'idler pulley 5 both rotatable about `parallel horizontal aires; anelongated arcuate series or bami ofrmagnetsf having lower poles or'pole-pieces'y 1 disposed incluse proximity to the top of the lowerstretch or run 8 of the belt 3; a mixed material feed tray il fordelivering a granular mixture of magnetic and nonmagnetic particlessuspended in liquid, to the lower face of the belt run 3 near the idlerpulley a non-magnetic material or tailings hopper Iii forming a liquidbasin II at the delivery end of the feed tray 9 and in which the medialportion of the belt run ii is constantly immersed; a stationary magneticmaterial or concentrate guiding and squeeze plate I2 extending upwardlyfrom within the basin I I along and gradually approaching but spacedfrom the lower face of the belt run 3 remote from the feed tray 9, andcooperating with a special end pole I3 at its uppermost delivery end; aconcentrate discharge hopper i4 cooperating with a discharge spout I5 atthe upper end or" the squeeze plate I2; a motor I and speed reductiongearing I'I cooperating with the upper pulley 4 to constantly drive thesame and to thereby likewise advance the belt 3 at any desired speed; amanually manipulable belt tghtener i8 cooperating with the idler pulleyto initially tension the belt; and an automatic belt tensioning andcontact roller I9 coacting with the upper belt run near the drivingpulley The various parts of the improved separating unit are mountedupon a sturdy main frame 2l, and the pulleys Il, 5 are journalled forrotation in xed and adjustable bearings 2.2, 23 respectively carried bythe upper portion of the frame 2i, while the magnets t are enclosedwithin a sealed casing 2li which together with the hoppers Il), I andthe feed and discharge elements are secured to the opposite side wallsof the main frame. The endless conveyor belt 3 is preferably formed ofdurable rubber or similar resilient material, and the lower run 8 ofthis belt should snugly engage but be freely slidable along thepole-pieces l, I3 and the intervening spacer blocks 25 or" the magnets 5which may be electrically energized in a well known manner to produceopposite polarity in the successive polepieces l, I3.

The mixture of magnetic and non-magnetic particles suspended in liquid,may be constantly fed to the feed tray e through one or more supplypipes 2t and a distributing chamber 2l, and the tray .fl is spaced frombut substantially follows the curved contour of the lower advancing beltrun 8, terminating within the liquid basin II.

In order to permit variation of the level of the I liquid which ismaintained within the basin II and in which the medial portion of thebelt stretch il is immersed, the tailings discharge hopper Ie isprovided at its bottom with an adjustable outlet 28, and an overflowopening 29 at the f upper portion of the hopper Iii beneath the squeezeplate serves to discharge excess liquid from the basin I l which is notcarried off by the outlet 23.

The inclined squeeze plate I2 gradually aptends approximately parallelto the pole-piece I3` Y;

throughout the entire extent of the latter. The tapered area above thelower portion of the plate I2 serves as a washing and pick-up zone forthe magnetic particles or concentrates, while the more restricted areadirectly beneath the special pole I3 functions tofcompress and tosqueeze excess polluted liquid out of the mass of concentrates and toreturn this liquid down the inclined plate I2 to the basin iI. The lowerextremity of the concentrate discharge hopper It is provided with aconcentrate outlet 3Q and the delivery spout I5 at the end of the plateI2 is directed downwardly toward this outlet.

The housing for the separating zones and which constitutes a part of themain frame ZI, is provided with inspection openings 3I near the feed anddischarge zones, so that an attendant may readily observe thefunctioning of the machine; and this housing is also provided with freshliquid sprayinlets 32, 33, one of which serves to deliver a spray ofclean liquid upon the inner surface of the advancing belt 3 While theother likewise projects cleansing liquid against the outer belt surface.The belt tightener I8 for initially tensioning the belt 3 is mountedupon vthe upper forward end of the main frame 2| and comprises amanually manipulable screw 35 coacting with each of the bearings 23 ofthe idler pulley 5, and with a bracket 36 so that rotation of the screws35 will slide the corresponding bearings along parallel slots 3l formedin the opposite sides of the bracket 36. The screws 35 are adapted to belocked in adjusted position relative to the bracket 36 by means of nuts38, and the initial belt tensioning effected with the aid of thistightener I3 may be accomplished whenever the separator is firstassembled or when a new belt 3V is applied to the pulleys 4, 5. v

The automatic belt tensioning and con-tact roller I9 which coacts withthe upper belt stretch or run near the driving pulley 4, functions notonly to compensate for subsequent wear and stretching of the belt 3, butalso serves to mate- -rially increase the driving con-tact between thepulley 4 and the inner belt surface considerably beyond The roller I9 isrelatively heavy and rests by gravity upon the upper run of the belt 3,being journalled for free rotation in a pair of laterally spaced levers40. The levers 40 are swingably mounted upon a transverse pivot rod 4Icarried by bracket member 42 supported upon the upper deck of the mainframe 2|, and the swinging end of each lever 40 beyond the roller I9 isprovided with alongitudinally adjustable Weight 43. These weights 43Vaugment the pressure exerted by the roller I9 against the belt 3, andthey may be adjusted independently of each other in order to equalizethis pressure throughout the belt width. l

When the improved endless belt magnetic separating unit has beenYproperly constructed, assembled and adjusted as above described, itsnormal operation is as follows. The propelling motor I6 may be operatedto rotate the pulley'4 at the desired speed, thereby constantlyadvancing the endless belt'3 in the direction indicated by the arrow.The magnets 6 should be'energized and fresh liquid should be admittedthrough the inlets 32, 33 whereupon liquid containing the mixture ofmagnetic particles and non-magnetic substances may be constantlysupplied through the feed pipe 26 and chamber 2'I to the-feed tray y9.As the feed mixture flows along vand over the end of the tray 9 lbeneaththe advancing lower run 8 of the belt 3 and through the magnetic iieldproduced by the magnets, the particles of magnetic material will beattracted by the successive pole-pieces I and will adhere to the lowerouter belt surface. I- f The liquid admitted with the feed mixture byregulating the outletfvalve l28, while excessive Erising 4 0f thisliquid level `willbe-:avoided lby the overflow opening v 2 9. Asfthe'belt' run "B proceeds throghffthe vliquid basin "Iig-the vmagnet poles'I whichare{if-successive opposite polarity,` will 'tend itc 'agitatethe magnetic 'particles adhering the -Ibelt l 3 thus Washingv`7t1"1"e1"ef10m I entrai-fled onrri'agnetic particles A and othersubstances which descend through the-hopper IIl'-wilth: the

liquid. Upon reaching the discharge plate l2, the advancing magneticparticles adhering to the 'belt run 8 will be carried through thetapering liquid filled space produced by the lower end o-f the plate I'2cooperating with the adjacent portion of the -advancing belt, and theseparticles will be gradually positively confined within the field ofmagnetic influence produced by the magnets so that any magneticparticles which may be dislodged from the belt surface will promptly bepicked up and restored to this surface.

The magnetic lparticles clinging to the belt 3 will eventually becarried upwardly along the plate I2 above the level of the liquid in thebasin I I and will thereafter be subjected to a confining and squeezingaction by the plate I2 and the powerful magnetic influence of theconsiderably wider pole-piece iI3. This compression or squeezing of theconcentrates will express lthe polluted liquid therefrom and the removedliquid will flow down the spaced inclined plate I2 into the basin I Iwhile the clean magnetic concentrates will drop by gravity from the belt3 onto the spout I5 after they pass the zone of `magnetic influencecreated by the magnets, 6. The fresh liquid spray admitted through theinlet 33 will then wash the louter surface of the belt 3 lbefore thisbelt proceeds beneath the automatic tensioning roller I9, and this freshwashing liquid will also assist in carrying the concentrates down thespout I5 to the outlet 30; while the fresh liquid spray admitted throughthe inlet 32 will also wash the inner surface of the belt 3 free fromabrasive particles and will lubricate the surfaces of the magnetic poles1, I3 thereby reducing friction losses to a minimum.

While the belt tightener I8 may be adjusted .to initially tension theendless belt 3 and to maintain the lower arcuate run 8 thereof in properengagement with the pole-pieces 1, I3 and spacer blocks 25, the flexiblebelt 3 may contract or stretch slightly, and 4may also wear somewhatduring normal operation. In order to avoid necessity of constantlywa-tching for such changes in the belt length, the roller I9 willautomatically compensate Afor such variations, and theweights 43 may bereadily adjusted to produce the desired belt tension. By locating theroller I9 in close proximity to the d-riving pulley 4, additional andmost effective driving contact between the rpulley 4 and the `belt isalso obtained and undesirable slippage is avoided. The unit will thusfunction most effectively with very little attention, and the normaloperation may be observed through the openings 3| while the feed inletand tailings discharge may be controlled so as to insure maximumefficiency and capacity of the unit.

' From the foregoing detailed description it should be apparent that myinvention in fact provides an endless belt magnetic separator "winni 'issentie, @maar and cutan inf-construction `andwhich 'is also highlyleiiicierit in loperation and flexible in its adaptation for-thetreatment Y'of variable mixtures of magnetic and non-magnetic particles.With the aid of the vcombined manual 'and automatic lbelt'tensi'oning vfl'cviatingv belt tensioning roller I9 also vca1 1se's t lce belt 3'tocontact the ,driving-pulley 4 'for aconsiderable portion'of the 'pulleyperiphery. vflfie improved 'squeeze plate A'I2 also insures theproduction of clean and unadulterated concentrates without causing theseconcentrates to cling to the belt after leaving the magnetic field,while the overflow opening 29 located beneath this plate permitsdischarge of excess polluted liquid entirely within the unit where thisliquid may be conducted away with the tailings. All parts of theimproved assemblage are also well protectedwhile still being readilyaccessible for inspection, and the structure has proven highlysatisfactory and successful in actual use especially for the treatmentof low grade iron ore.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode of operationof the magnetic separator herein specically shown and described, forvarious modifications within the scope of the appended claims may occurto persons skilled in the art.

I claim:

l. In a magnetic separator, horizontally spaced pulleys, a series ofelectro-magnets located between said pulleys and having poles formed tocreate an arcuate magnetic field the medial portion of which extendsdownwardly below the lowermost portions of both of the pulleys, anendless conveyor belt coacting with said pulleys and having its lowerrun longitudinally movable through said eld and along said magnet poles,means forming a liquid basin within which the medial portions of saidbelt run and of said magnetic field are immersed, means for feedingmixed magnetic and non-magnetic particles toward the lower face of saidbelt run at one end of said basin, and a substantially straight andimperforate inclined guide plate of non-magnetic material having itslower end immersed within the liquid near the opposite end of said basinand its upper end portion gradually approaching said belt run andterminating above said liquid closely adjacent to the last pole of saidmagnet series, said last pole also being above said liquid andcooperating with its renergizing magnet to produce increased fluxintensity at the point of glosest approach of said plate toward saidbelt ace.

2. In a magnetic separator, horizontally spaced pulleys, a series ofelectro-magnets located between said pulleys and having poles formed tocreate an arcuate magnetic field the medial portion of which extendsdownwardly below the lowermost portions of both of the'pulleys, anendless conveyor belt coacting with said pulleys and having its lowerrun longitudinally movable through said eld and along said magnet poles,

the lower face of said belt run at one end of said 5 basin, asubstantially straight and imperforate inclined guide plate ofnon-magnetic material having its lower end immersed within the liquidnear the opposite end of said basin and its upper end portion graduallyapproaching said belt run and terminating above said liquid closelyadjacent to the last pole of said magnet series, said last pole alsobeing above said liquid and cooperating with its energizing magnet toproduce increased iiux intensity at the point of closest approach ofsaid plate toward said belt face, and means forming an overflow forexcess liquid from said 'basin directly beneath the medial portion ofsaid inclined guide plate.

STANLEY G. INJESKI.

8 Referencesited in theflle 01' this patent UNITED STATES PATENTS NumberVName Date Nickerson Jan. 5, 1897 Conley Nov. 14, 1899 Dutton July 13,1915 Brackett Sept. 11, 1928 Brubaker Sept. 13, 1932 Crockett Nov. 5,1946 Martin June 10, 1947 Niedener Dec. 30, 1947 Crockett Aug. 10, 1948Stearns June 13, 1950 Vogel Aug. 14. 1951

